(2) Replacement of Muffle.
(a) Replace the insulating sleeves over the wire. Insert the muffle (5) with the hole for the thermocouple
toward the top of the furnace. Replace the insulating blocks (3) over the rear of the muffle.
(b) Replace the terminal plate, drawing lead wires through holes.
(c) Attach leads to the terminals.
(d) Attach the thermocouple (4) to the instrument in the base, making sure that each wire goes to the terminal
from which it has been removed. Replace metal air vent with spring in hole. Stand the furnace up. Open the hole from
inside of the muffle and insert the thermocouple.
(e) Replace the loose insulation blocks (3).
(f) Replace the backplate (2) and tighten three screws (1).
5-6. REID VAPOR PRESSURE BOMB BATH.
a. Lubricating. Oil the stirrer motor approximately every 4 months using a good grade of light machine oil (PL-S).
b. Cleaning. Wipe all components with a clean, damp cloth.
c. Checking Thermoregulator. Inspect the thermoregulator closely for presence of gas bubbles in the mercury
column. If bubbles or separation of mercury in column exist, heat the bulb gently until bubbles are driven up into the
expansion chamber. Cool slowly in a vertical position, allowing the mercury to recede slowly to form a solid column
without bubbles or separation.
d. Calibrating Thermoregulator. Immerse thermoregulator in the bath at a temperature lower than that at which the
bath is to be regulated. Place a calibrated ASTM No. 18F thermometer in the bath. Bring the bath temperature up to 96
degrees F to 98 degrees F (35.5 degrees C to 36.4 degrees C). Rotate the microset magnetic coupler until the indicator
light on the control box is extinguished. Rotate the magnetic coupler until the indicator light is on. Continue making
minor adjustments until the bath temperature is maintained at the desired temperature (100 degrees F +0.2 or -0.2
degrees F) (37.7 degrees C +17.6 degrees C or -17.6 degrees C).
e. Troubleshooting. The operator should be guided by the following chart (table 5-2) in diagnosing and correcting